ABSTRACT
The accuracy of Free-floating particles (FFPs) and biparietal diameter (BPD) detected and measured by ultrasonography for assessment of fetal lung maturity were compared with the lecithin/sphingomyelin (L/S ratio) which was used as the gold standard. One hundred pregnant women in the lately third trimester who required amniocentesis for fetal lung maturity testing, from July 1998 to August 1999 at Siriraj Hospital, were included in this study. Ultrasonography was performed to evaluate the presence of FFPs in the amniotic fluid and the BPD was measured. Amniotic fluid for L/S ratio was obtained by amniocentesis. The presence of FFPs had a 58.3% specificity and a 41.7% false positive rate. A BPD value of at least 94 millimeters had 100% specificity and no false positives. When the presence of FFPs and a BPD value of at least 93 millimeters were used in combination, the test gave 100% specificity and no false positives. The presence of FFPS and a BPD value of at least 93 millimeters detected by real time ultrasonography may be used as predictive parameters to indicate fetal lung maturity.
ABSTRACT
The examination of amniotic fluid for the presence or absence of free-floating particles (FFPs) by real-time ultrasound was performed in 100 non-diabetic patients undergoing amniocentesis for maturity testing. A modified lecithin to sphingomyelin ratio (L/S ratio) was the gold standard of the test. The sensitivity and specificity were 97.6% and 62.5% respectively. The presence of FFPs had 93.2 positive predictive value and 83.3% negative predictive value. FFPs grade 2, 1, 0 had 100%, 70% and 16.7 positive predictive value respectively. The mean value of L/S ratio varied with the FFPs grading, with the mean of 5.09+ 2.48, 2.84 + 0.71, 2.02+ 0.01 in grade 2, 1 and 0 respectively. This study suggests that the presence of FFPs especially FFPs grade 2 on real-time ultrasound may be used to confirm fetal lung maturity.